Combined multirate-based and fir-based filtering technique for room acoustic equalization
US8077880B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 2007 |
| Grant date | Dec 13, 2011 |
| Priority date | — |
| Expiry date | Jun 29, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04S3/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A combined multirate-based Finite Impulse Response (FIR) filter equalization technique combines a low-order FIR equalization filter operating at a lower rate for equalization of a loudspeaker-room response at low frequencies, and a complementary low-order minimum-phase FIR equalization filter operating at a higher rate for equalization of the loudspeaker-room response at higher frequencies. The design of two complementary band filters for separately performing low and high frequency equalization, keeps the system delay at a minimum while maintaining excellent equalization performance. Splicing between the two equalization filters, for maintaining a flat magnitude response in the transition region of the two complementary filters, is done automatically through level adjustment of one equalization filter relative to the other. The present invention achieves excellent equalization at low filter orders and hence reduced computational complexity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.